Chromatographic detection of sesquiterpene lactones in Parthenium plants from Northwest Argentina

Several chloroformic extracts containing some sesquiterpene lactones from a utochtonous plants of Parthenium hysterophorus, collected in the province o f Salta (Argentina), were separated and identified by high performance reve rsed-phase liquid chromatography with C-18 column and propanol-water mobile phases, using gradient elution and concentrations of propanol larger than 10% (v/v). Lactones previously purified and characterized by H-1 RMN, C-13 RMN, IR, and mass spectrometry, were used as standards. The objective of the study was to check if the nature of the lactones was m odified according to the altitude of the region where the plants were grown . Among the lactones, five were already described: coronopilin, hymenin, hy sterin, parthenin, and tetraneurin A. p-Methoxybenzoic acid and two new amb rosanolides were also detected. Tetraneurin A and hymenin, on the one hand, and parthenin and coronopilin, on the other, were better resolved with a m obile phase of 6% propanol, run during 45 min.